Transient Ischemic Attack

1. See Also
   1. Ischemic CVA
2. Pathophysiology
   1. General
      1. Vascular related focal cerebral dysfunction
   2. Spectrum
      1. Transient Ischemic Attack (TIA)
         1. Temporary cerebral dysfunction
         2. Duration less than 24 hours (usually <10 minutes)
      2. Cerebral Infarction with Transient Signs (CITS)
         1. Partially reversible, non-disabling stroke
      3. Ischemic Cerebrovascular Accident
         1. Non-reversible stroke
3. Causes
   1. See Transient Ischemic Attack Causes
4. Risk Factors
   1. See TIA Risk Factors
5. Symptoms and Signs
   1. Timing
      1. Carotid TIAs resolve within 14 minutes
      2. Vertebral TIA resolve within 8 minutes
      3. Symptoms persisting >1 hour: 2-14% resolve in 24 hours
      4. Albers (2002) N Engl J Med 347(21):1713-6
   2. Anterior circulation symptoms (Carotid Artery)
      1. See Anterior Cerebral Artery CVA
      2. See Middle Cerebral Artery CVA
      3. Transient Monocular Blindness (Amaurosis Fugax)
      4. Clumsiness, weakness or numbness of hand
      5. Speech changes
   3. Posterior circulation symptoms (Vertebro-basilar)
      1. See Posterior Inferior Cerebellar Artery CVA
      2. See Vertebro-Basilar CVA
      3. See Posterior Cerebral Artery CVA
      4. Binocular vision changes or Diplopia
      5. Vertigo, ataxia or light headedness
      6. Dysarthria
      7. Generalized weakness
      8. Loss of consciousness
      9. Transient global amnesia
6. Evaluation
   1. Urgently evaluate new onset TIA within hours to days
      1. Stroke follows TIA within 90 days in 20-25% of cases
      2. See Prognosis below for studies regarding risk
   2. History
      1. Evaluate differential diagnosis (see Ischemic CVA)
      2. Evaluate risk factors (see Ischemic CVA)
      3. Determine anterior or posterior circulation (above)
      4. Determine probable source (see causes above)
   3. Examination
      1. Thorough cardiovascular examination
         1. Assess for Carotid Bruit
         2. Funduscopic Examination
         3. Assess for Atrial Fibrillation
         4. Assess for Heart Murmur
         5. Assess for Hypertension
      2. Thorough Neurologic Examination
         1. Often normal if TIA has completely resolved
7. Labs
   1. Initial
      1. Complete Blood Count (CBC)
      2. Serum Glucose
      3. Serum Lipids
      4. Serum electrolytes
      5. ProTime with INR
      6. Partial Thromboplastin Time (aPTT)
   2. Other labs to consider
      1. Homocysteine
      2. Serum Folate
      3. Serum Vitamin B12
      4. Hypercoagulable state evaluation
         1. Indicated in age under 50 years
8. Imaging: First Line Evaluation (emergent, immediate)
   1. Head CT
      1. Head CT is the recommended study in acute CVA if Thrombolysis is being considered
      2. Identifies prior infarction or hemorrhagic CVA
      3. Identifies Brain Tumor and other CNS masses
9. Imaging: Second Line Evaluation
   1. Typical evaluation in first 24-48 hours
      1. MRI Brain
      2. Magnetic Resonance Angiography (MRA) of Brain and Neck
      3. Echocardiogram
         1. Transthoracic: Embolization suspected (see above)
         2. Transesophageal: Suspected emboli and negative echo
   2. Studies to consider on discharge
      1. Holter Monitor
         1. Identify suspected intermittent Atrial Fibrillation and not found on inpatient telemetry
   3. Other studies
      1. Carotid ultrasound for anterior circulation (or MRA Neck)
         1. MRA Neck has largely replaced carotid ultrasound in post-CVA assessment
         2. Carotid ultrasound is a good alternative when dictated by expense or MRI contraindications
         3. Carotid Stenosis <50% suggests other source
         4. Carotid Stenosis >50% (especially if >80%)
            1. Obtain carotid arteriogram or MRA
            2. Arteriogram or MRA confirms >70% stenosis: Surgery
            3. Arteriogram or MRA suggests 50-69% stenosis
               1. Consider surgery in lower risk patient
               2. Medical therapy in high risk patient
      2. Transcranial ultrasound for posterior circulation
      3. Arteriography
         1. Gold standard for pre-endarterectomy evaluation
10. Differential Diagnosis
    1. See Ischemic CVA
    2. Hypoglycemia
    3. Migraine Headache (including aura)
    4. Seizure disorder (including post-ictal period)
    5. CNS tumor
11. Management
    1. Immediate management of suspected TIA
       1. ER evaluation if symptom onset <48 hours ago
          1. See labs and radiology above
          2. See CVA Management if ongoing symptoms
          3. Consider for Thrombolytic management in CVA
       2. Urgent outpatient evaluation if >48 hours
          1. See labs and radiology above
          2. See Carotid Stenosis for Endarterectomy Indications
          3. See Prevention of Ischemic Stroke
    2. Inpatient evaluation criteria
       1. Cardioembolic source with Anticoagulation considered
          1. Acute MI with large wall motion abnormality
       2. Large or evolving Cerebrovascular Accident
          1. Severe neurologic deficit (e.g. dense Hemiplegia)
          2. TIA symptoms recurring at increasing frequency
       3. Vascular or neurosurgery consultation may be required
          1. High grade Carotid Stenosis suspected
          2. Possible Subarachnoid Hemorrhage
       4. High risk for CVA or TIA complications
          1. Aspiration Pneumonia
12. Precautions
    1. Transient Ischemic Attacks are not outpatient problems (evaluate in emergency or inpatient setting)
    2. Evaluate and manage TIA underlying causes (e.g. Carotid Stenosis) within 2 weeks of event
13. Prevention
    1. See Carotid Stenosis for Endarterectomy Indications
    2. See Prevention of Ischemic Stroke
14. Prognosis
    1. Adverse events occur in 20-25% with TIA within 90 days
       1. CVA represents 10% of these adverse events
       2. 50% of CVAs occurred within 2 days of TIA
    2. References
       1. Coull (2004) BMJ 328:326-8
       2. Johnston (2000) JAMA 284:2901-6
15. References
    1. Pruitt in Goroll (2000) Primary Care, p. 970-4
    2. Beauchamp (1999) Radiology 212(2):307-24
    3. Adams (2007) Stroke 38(5): 1655-711
    4. Bernheisel (2011) Am Fam Physician 84(12): 1383-88
    5. Biller (2000) Am Fam Physician 61(2):400-6
    6. Eugene (1999) Geriatrics 54(5):24-33
    7. Flemming (2000) Postgrad Med 107(6):55-80
    8. Hemphill (2000) Geriatrics 55(3):42-52
    9. Riggs (1998) Surg Clin North Am 78(5):881-900
    10. Ryan (1999) Am Fam Physician 60(8):2329-41
    11. Sacco (1998) Neurology 51:S27-30
    12. Solenski (2004) Am Fam Physician 69:1665-80